Name: __________________________________ Period: ______
Lab: Assembling and Explaining Meiosis
Introduction
Cell division is how organisms grow and repair themselves. It is also how they produce offspring. Many single-celled
organisms reproduce by binary fission. The parent cell simply divides to form two daughter cells that are identical to the
parent. In many other organisms, two parents are involved, and the offspring are not identical to the parents. In fact,
each offspring is unique. The children resemble their parents, but they are not identical to them. Instead, each has a
unique combination of characteristics inherited from both parents.
Sexual reproduction involves two parents. In sexual reproduction, parents produce reproductive cells—called
gametes—that unite to form an offspring. Gametes are haploid cells. This means they contain only half the number of
chromosomes found in other cells of the organism. Gametes are produced by a type of cell division called meiosis. The
process in which two gametes unite is called fertilization. The fertilized cell that results is referred to as a zygote. A
zygote is diploid cell, which means that it has twice the number of chromosomes as a gamete.
The process that produces haploid gametes is meiosis. Meiosis is a type of cell division in which the number of
chromosomes is reduced by half. It occurs only in certain special cells of the organisms. During meiosis, homologous
chromosomes separate, and haploid cells form that have only one chromosome from each pair. Two cell divisions occur
during meiosis, and a total of four haploid cells are produced. The two cell divisions are called meiosis I and meiosis II.
The overall process of meiosis is summarized in the Figure below.
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Part One: Assembling Meiosis
Materials
 Compass
 2 Large sheets of white paper (use the one from
 Colored pencils
Mitosis lab and a blank new sheet)
 Pencil
 4 different colors of pipe cleaners (use your
 Computer: Textbook (OL: pgs. 18-21;
Chromosomes from the Mitosis lab); additional strips
HC: pgs. 12-14 , PowerPoint (slides 30Of same colored pipe cleaner to assemble
34; NOTE THESE PICTURES DO NOT
crossing-over
ALL SHOW 4 CHROMOSOMES)
 4 round beads (centromeres from Mitosis lab)
 1 Ziploc bag with Mitosis materials in
 2 3-pronged beads (centrioles from Mitosis lab)
it
 1 Bead necklace (nuclear membrane/ envelope from
Mitosis lab)
 Scissors
 Ruler
1. Assign the tasks in the chart below to each group member. You will be evaluating each other’s contributions
when the lab is complete.
Tasks
1. Gather groups computers
2. Gather materials needed
3.Assemble chromosome pieces, nuclear membrane pieces,
and additional pipe cleaners that will be needed
4. Draw phase circles on large white sheet & label
5. Answer questions on pages 1 & 3 of the lab
Group Member Assigned
1.
2.
3.
4.
5. ALL GROUP MEMBERS COLLABORATIVELY
2. Cut 1 piece of pipe cleaner 1” long from each color of pipe cleaner. You will end up with four 1” sections of each
color. DO NOT DISCARD YOUR EXTRA PIECES OF PIPE CLEANER.
3. You will pencil-draw in the spindles where needed.
4. You will need to re-label your sheet from the Mitosis lab as shown below:
Meiosis I
Prophase I
Anaphase I
Cytokinesis I
Metaphase I
Telophase I
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5. On your second white sheet of paper (in pencil) draw & label it as shown below:
a. 4 Large circles under meiosis II should be drawn with your compass and have a 3 ½ ” diameters
b. The smaller circles of cytokinesis II should have 2 ” diameters
Meiosis II
Prophase I I
Telophase I I
Metaphase I I
Anaphase I I
Cytokinesis I I
6. Now in the chart below assign each person in your group a phase of mitosis:
Phase
Group Member
1. Prophase I
2. Metaphase I
3. Anaphase I
4. Telophase I
Cytokinesis I
5. Prophase II
6. Metaphase II
7. Anaphase II
8. Telophase II
Cytokinesis II
7. You will need to show all four sister chromatids crossing-over. Use your resources to remember which phase
crossing-over happens in.
8. Take turns practicing and explaining what happens in each of your assigned phases using the materials provided
on the large sheets of white paper. You may use your textbooks to help you. When you think you are ready call
an instructor over so that as a group you can demonstrate and explain Meiosis I, Meiosis II, Cytokinesis I, and
Cytokinesis II; scores will be recorded on the rubric on page 7 of this lab.
9. You are now ready to complete Part Two below.
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Part Two: After you have assembled and explained mitosis & cytokinesis to your instructor on the big sheet of white
paper transfer that information (using colored pencils to match the colors of pipe cleaners you used) by drawing each
phase’s activities onto the diagrams below. On the blank lines provided next to each phase; list the events of the each
phase.
MEIOSIS I:
Prophase I
1. ______________________________________________________________
2. ______________________________________________________________
3. ______________________________________________________________
4. ______________________________________________________________
5. ______________________________________________________________
6. ______________________________________________________________
Metaphase I
1. ______________________________________________________________
2. ______________________________________________________________
Anaphase I
1. ______________________________________________________________
2. ______________________________________________________________
3. ______________________________________________________________
Telophase I
1. ______________________________________________________________
2. ______________________________________________________________
3. ______________________________________________________________
Cytokinesis I
1. _______________________________________________________
2. _______________________________________________________
3. _______________________________________________________
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MEIOSIS II:
Prophase II
1. ______________________________________________________________
2. ______________________________________________________________
3. ______________________________________________________________
Metaphase II
1. ______________________________________________________________
2. ______________________________________________________________
Anaphase II
1. ______________________________________________________________
2. ______________________________________________________________
Telophase II
1. ______________________________________________________________
2. ______________________________________________________________
Cytokinesis II
1. _______________________________________________________
2. _______________________________________________________
3. _______________________________________________________
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PART THREE: Conclusions and Analysis
1. Define gamete and zygote. What number of chromosomes does each have?
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
2. What happens during fertilization?
___________________________________________________________________________________________
___________________________________________________________________________________________
3. What is gametogenesis, and when does it occur?
___________________________________________________________________________________________
___________________________________________________________________________________________
4. Create a diagram (PICTURE) to show how crossing-over occurs and how it creates new gene combinations on
each chromosome.
5. Explain why sexual reproduction results in genetically unique offspring.
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
6. Explain how meiosis I differs from mitosis.
___________________________________________________________________________________________
___________________________________________________________________________________________
___________________________________________________________________________________________
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SCORE ON PRESENTATION:
Phase
Prophase I
1
Only 1 event accurately explained
and manipulated using the model
Metaphase I
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Anaphase I
Telophase I
Cytokinesis I
Prophase II
Metaphase
II
Anaphase II
Telophase II
Cytokinesis
II
Score Totals
Final
Score
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
Only 1 event accurately explained
and manipulated using the model
2
Less than 6 events accurately
explained and manipulated using
the model
Both events inaccurately explained
and manipulated using the model
Only 2 events accurately explained
and manipulated using the model
Only 2 events accurately explained
and manipulated using the model
Only 2 events accurately explained
and manipulated using the model
Less than 3 events accurately
explained and manipulated using
the model
Both events inaccurately explained
and manipulated using the model
Both events inaccurately explained
and manipulated using the model
Both events inaccurately explained
and manipulated using the model
Only 2 events accurately explained
and manipulated using the model
3
All 6 events accurately explained and
manipulated using the model.
Both events accurately explained and
manipulated using the model.
All 3 events accurately explained and
manipulated using the model.
All 3 events accurately explained and
manipulated using the model.
All 3 events accurately explained and
manipulated using the model.
All 3 events accurately explained and
manipulated using the model.
Both events accurately explained and
manipulated using the model.
Both events accurately explained and
manipulated using the model.
Both events accurately explained and
manipulated using the model.
All 3 events accurately explained and
manipulated using the model.
/15
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